Ouch, that hurts!

In spite of the somewhat appropriate title, this post is not about what STFC thinks about the LHCb experiment.


While I was searching for some material from my lecture at next week's Master Class I found the picture on the left. It's taken from the first episode of the the Big Bang Theory, a new sitcom now aired on Channel 4. For those who don't know it, it's basically like Friends, just with only nerds.

In the depicted scene (watch it) main character Sheldon supposedly explains some string theory to his neighbour Penny. A closer inspection shows that the white board has little to do with string theory. There's a simple calculation of the decay rate of the top quark to the bottom quark (assuming CKM unitarity) and then two Feynman diagrams of "FCNC" (flavour changing neutral current) top quark radiative decays. Finally there's a partial view of the CKM matrix. This scribble on this nerdy sociopath's white board could actually have been copied from my own white board (I mean, the one in my office). Ouch, that hurts!

The LHCb group at Imperial specialises in FCNC decays (actually of the b quark) as it is a very promising way of indirectly observing new particles too heavy to be accessed directly at a collider. They can hide in the loops shown on the picture (more). Many particles have been "discovered" indirectly this way before being actually produced directly at a collider. The race between direct and indirect will be on again when the LHC turns on.